Novel crown ethers on glucose based glycolipids

A series of crown ethers involving lauryl glucoside were synthesized and their assembly behavior in water was studied. The synthesis applied a simple protection scheme based on benzylidenation for the glycolipid, and cation templating for the macrocycle. A sequential build-up of the crown ether by bis-hydroxylethylation of the glucoside followed by reaction with di-, tri-, or tetraethylene glycol ditosylate provided better yields of the macrocycle compared to a single step cyclization with tetraethylene glycole ditosylate. The macrocycles containing up to six oxygens showed significantly higher affinity for sodium than for potassium, while more effective potassium complexation was found for the 21-crown-7 compound. The ion binding affinity leads to a slight but significant increase of the CMC of the crown ether containing surfactant in water upon the addition of sodium electrolyte.